Latch operated clutch



June 6, 1950 v. cHMr-:LA

LATCH CPERATED CLUTCH Filed Deo. 3, 1948 part of the eye I6 has screwed thereon a washer 26 with which the nose 23 is in contact. The lower part of the pawl I8 is provided also with a socket 21 in which a spring 28 is lodged, the other end of the spring being threaded on a stud 29 fastened on the bracket 2B. The spring 28 urges constantly the locking pawl I8 to the right, as viewed in Figure 3, that is to say in counterclockwise direction.

The bracket 20 carries also a pin 38 which passes through a longitudinal slot 3I provided in a lever 32, whose one end projects through an opening 33 out of the bracket 28 and has a nose 34, while the other end of the lever 32 has connected thereto a spring 35 which constantly tends to pull the lever to the right. That end of the lever 32 which is provided with the nose 34 passes :through the forked portion 24 of the pawl I8, .the arrangement being such that in the initial jposition the nose 34 engages in the recess 25 of the nose =23.

On the pivot pin 35 of the lever 32 is mounted a draw bar 3l which is controlled by a start- :ing lever 38, Fig. 5, actuated by the assistants knee, the control being effected through the intermediary of a double-armedv lever 39 rotatably mounted about a pivot pin 48 on the machine frame.

The described mechanism operates as follows:

In .the initial position, when the machine is not in operation, the clutch of the driving device occupies the position shown in Fig. l and the starting mechanism occupies the position shown in Fig. 2. In this positionthe pulley I rotates freely and does not drive the shaft 3 because thefriction clutch is not expanded, since the hollow pin I for actuating the key E is in its right hand extreme position, in which it retained by the bevelled finger I3 of the triple-armed lever I4, the finger occupying the position shown in full lines in Figure 2. In this initial position, the eye I6 of the triple-armed lever I4 is held over the washer 23 against the nose 23 of the locking pawl I8, the spring 2I being compressed. Thus the locking pawl I8, and the lever 32 as well, occupy their right hand extreme positions as shown in Fig. 3.

If a working stroke is to be effected, the assistant exerts pressure with his knee on the starting lever 38 in the Adirection of the arrow shown in Figure 5, whereby the lever 32 is pulled to the left on the pin 33 through the intermediary of the double-armed lever 3S and the draw rod 3l. As result of this movement, the lever 32 which by means of its nose 34 engages in the recess 25 of the locking pawl I 8, causes the latter to turn about the pivot I2 in clockwise direction,.where by the nose 23 is disengaged from beneath the 'washer 26 of the eye It, so that the compressed spring 2| can depress the eye I5 and cause the triple-armed lever I4 to turn in a `counter-clockwise direction (as viewed lin Fig. 2) to the position shown in dotted lines. In this position of the lever I4, the bevelled finger I3 of the same is out of contact with the hollow pin l which then is shifted to the left, as viewed in Fig. l, under the effect of the spring I2 and causes the screw key 6 to turn in clockwise direction whereby the friction clutch 5 is expanded and pressed against the drum 4. In this way connection is established between the pulley I and the driving shaft 3 and a working stroke takes place. 1

For effecting a working stroke, a single revolutionof the shaft 3 is required and upon completion of the revolution it is always necessary' to interrupt the connection of the shaft with the pulley I, so as to avoid a repetition of the working stroke and a possible injury of the assistant. No further working stroke should take place even if the assistant keeps the starting lever 38 in depressed position. For the sake of his safety, the assistant must rst release the starting lever and then depress it again if another working stroke is required.

Assuming that the assistant has released the starting lever 38, the disengagement of the clutch is effected as follows: The eccentric 8 whose initial position is shown in solid lines in, Fig. 2, is

rotated by the shaft 3 in counterclockwise direction until it reaches the position shown in dotted lines in which the eccentric acts upon the roller I'I in such a way as to rock the triple-armed lever I4 in lclockwise direction from the position shown in dotted lines in Fig. 2 to its initial position, the spring 2I being compressed again at the same time. At this moment the locking pawl I8 rocks under the effect of the compressed spring l28 to the right from the position shown in Figure 4 to its initial position shown in Fig. 3, in which the pawl I8 engages beneath the washer 26 on the eye I6 of the triple-armed lever I4 and holds rigidly the latter in this position during the remaining part of the revolution of the shaft 3, that is also during the period when the eccentric 8 does not -co-operate any longer with the roller Il. If the starting lever 38 has been released, the movement of the locking pawl I8 to the right is accompanied by movement of the lever 32 under the action of the spring 35 so that the starting device will reassume its neutral position shown in Figure 3. When the shaft 3 with the eccentric 8 arrive to the position shown in solid lines in Figure 2, the bevelled finger I3 of the triple-armed lever I4 is positioned in the path of the hollow pin 1, the bevelled face of the finger I3 causing the hollow pin 'I to be shifted to the right so that the screw key 6 is rotated to the right. .As a consequence the friction clutch 5 is contracted, the connection with the drum 4 of the pulley is removed and the shaft 3 is arrested by a conventional brake (not shown).

Assuming that forany reason the assistant omits to release the starting lever 38, the shaft 3 mustbe arrested nevertheless so as to avoid a repetition of the working stroke of the stamping arm. In such a case the lever 32 remains in its position shown in Fig. 4 while all the other parts perform the aforementioned operations. The movement of .the pawl. I8 to the right without simultaneous movement of the lever 32 is made possible by the forked portion 24 which passes freely over the nose 34 of the lever 32. The nose 23 ,of the lpawl I8 engages again beneath the washer 23 of the eye I6 and the bevelled fnger I3 of thetriple-armed lever I4 by its action upon the hollow pin I interrupts in the described manner the connection between the. pulley I and theY shaft 3.

If in the case just referred to the assistant wishes to provoke another working stroke, he must first release the starting lever 38 whereby the lever 32 under the inuence of the tension of the spring 35 will return to its initial position shown in Figure 3, in which the nose 34 engages in the recess of the pawl I8. During this back movement the lever 32 performs also a small rotation about the pivot in a counter-clockwise direction, which rotation is permitted by the spring being anchored beneath the pivot 30 and tending constantly to rotate the lever 32 in this direction. By a further depression of the starting lever it is now possible to eiiect another working strokeiri the aforedescribed manner.

What I claim is:

1. In a, starting mechanism for power driven stamping machines provided with a one revolution clutch, the provision in the control lever system between a starting member operated by the assistant and the clutch operating member, of a triple-armed lever having one of its arms provided with an eye at the outer end thereof, a retaining pawlhaving a nose adapted to engage with said eye of the lever, cam means cooperating with the other two arms of said lever positively in opposite directions during one revolution of the clutch, a spring urged operating pin for the clutch, abevelled finger on the triplearmed lever for operating the pin, the said rst mentioned arm of the triple-armed lever being arranged to be retained by, or released from, the said pawl against` the action of a spring adapted to interrupt the connection of the said finger with the clutch operating pin, a slidable and partially rotatable lever co-operating with the said pawl and operated by a starting lever, and a iork formed at the Afree end of the said pawl and through whicha nose on the said slidable and partially rotatable lever is adapted to pass.

2. In a starting mechanism for power driven stamping machines provided with a one revolution clutch,` the provision in the control lever system between a starting member operated by the assistant and the clutch operating member,

' of a triple-armed lever having one of its arms provided with an eye at theouter end thereof, a retaining pawl having a nose adapted to engage with said eye of the lever, cam means cooperating with the other two arms of said lever positively in opposite directions during one revolution of theV clutch, a spring urged operating pin for the clutch, a bevelled nger on the triplearmed lever for operating the pin, the said ilrst mentioned arm of the triple-armed lever being arranged to be retained by, or released from, the said pawl against the action of a spring adaptedY to interrupt the connection of the said ilnger with the clutch operating pin, a slidable and partially rotatable lever co-operating with lil the said pawl and operated by a starting lever,

a fork formed at the free end of the said pawl and through which a, nose on the said slidable and partially rotatable lever is adapted to pass, a draw rod connected to a starting lever and controlling the movement of the said slidable and partially rotatable lever in one direction, and a spring anchored at a point beneath the last mentioned lever and controlling the movement of the latter in the opposite direction.

3. In a starting mechanism for power driven stamping machines provided with a one revolution clutch, the provision in the control lever system between a starting member operated by the assistant and the clutch operating member, of a triple-armed lever having one of its arms provided with an eye at the outer end thereof, a retaining pawl having a nose adapted to engage with said eye of the lever, cam means cooperating with the other two arms of said lever positively in opposite directions during one revolution of the clutch, a spring urged operating pin for the clutch, a bevelled finger on the triplearmed lever for operating the pin, the said rst mentioned arm of the triple-armed lever being arranged to be retained by, or released from, the said pawl against the action of a spring adapted to interrupt the connection of the said nger with the clutch operating pin, a slidable and partially rotatable lever co-operating with the said pawl and operated by a starting lever, a fork formed on the free end of the said pawl and through which a nose on the said slidable and partially rotatable lever is adapted to pass. a draw rod connected to a starting lever and controlling the movement of the said slidable and par- Y tially rotatable lever in. one direction, and a spring anchored at a point bene-ath the last mentioned lever and controlling the movement of the latter in the opposite direction, said cam being adapted, upon release of the said triple-armed lever from the nose of said pawl, to rock the said triplearmed lever against spring pressure so as to place the said bevelled finger in the path of the said clutch operating pin and to disengage the clutch independently of the position of the starting lever.

vAcLAv CHMELA.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,811,028 Ryan June 23, 1931 1,872,132 Falleson Aug. 16, 1932 2,259,297 Cramer Oct. 14, 1941 

